Radial medium truck (RMT) steer tires, in some cases, have been found to develop irregular internal rib wear. This undesirable condition can lead to early removal of tires from the vehicle. RMT steer tires typically have 4 to 6 solid ribs extending circumferentially about the tire. However, there can be any number of solid ribs. Internal rib wear generally happens very quickly if it is to be a problem. Steer tires that exhibit the irregular wear have been studied and compared to tires that have no history of developing such irregular wear in actual service. Data analysis has shown that internal rib wear on the RMT steer tires is related to high lateral slip and frictional energy acting upon the internal rib edges of the tire's tread at low severity conditions (zero lateral load). Lateral slip of the internal rib edges is believed to promote irregular wear mechanisms. The irregular wear begins as “river wear”, where the edges of the rib start wearing rapidly The irregular wear later propagates across the rib until the whole rib is worn (resulting in depressed internal rib wear). However, while the underlying mechanism seems well understood, it is difficult to determine the point at which a tire reaches the borderline values of total slip and frictional energy that will develop into internal rib wear.